1. Field of the Invention
This invention relates to interactive computer information display systems for displaying text or other visual information. Such systems are coming into widespread use, through information access systems such as the "Internet" World Wide Web (WWW). Large amounts of information are available to users having access to such systems. However, in order to gain access to such systems relatively expensive hardware is required, in particular a computer and a modem, limiting the availability of the information to users who have access to such a terminal. Furthermore, the hardware is typically bulky, and is not easily portable. Mobile systems, comprising a "laptop" computer and a cellular telephone, do exist, but because of the limited bandwidth available on mobile communications, these tend to be very slow.
2. Related Art
U.S. Pat. No. 5,236,199 (Thompson) and U.S. Pat. No. 4789895 (Mustafa) describe systems in which narrowband telephone links are used to control images presented via a broadband system (e.g. a cable television downlink), but in both cases the telephone lines are fixed, and dedicated to a specific display unit. These systems therefore require the user to have the use of such a device. Because the links are necessarily fixed it is not possible to use such an arrangement for a mobile user.
Multimedia "kiosks" have been proposed for locations to which the public have access. However, the equipment is valuable, and its accessibility to the public makes it vulnerable to theft, vandalism, and tampering. The equipment is also not suitable for exposed locations, as it is not in general weatherproof. In order to identify the user, and allow payment to be made for the service, facilities such as a credit card "swipe" unit and/or personal identity number (PIN) facility are also necessary. The use of PINs is vulnerable to people reading a genuine user's keystrokes as he enters his PIN, in order to subsequently use the PIN himself.